Aqueous effluents released from hydrothermal liquefaction (HTL) facilities may contain byproducts that include dissolved organic materials. Organic materials in the aqueous HTL effluents may be relatively dilute (˜2% carbon by weight) but also represent a large volume, constituting as much as 40% of the total carbon in the original biomass feedstock. Thus, recovery of these organic materials and reuse of the heated water stemming from these effluent streams is key to maintaining overall energy efficiency of biomass conversion. Accordingly, new approaches for processing of these aqueous effluent streams are needed. The present invention addresses these needs.